Signature gathering machine



Aug.v 6, 1957 s. T. sTooTHoFF ET'AL 2,801,845

SIGNATURE GATHERING MACHINE Filed Aug. 18, 1955. i 5 Sheets-Sheet l s .JM o .N mNuN WJ mm y M, w w. N B f @no Q@ 66T@ @Kev 6 Q o @Mnl @9.96 @L S1 EN L i S 3.? am ..5

Aug. 6, 1957 s, T. srooTHoFF Erm. 2,801,846

SIGNATURE GATHERING MACHINE Filed Aug. 18, 1955 5 Sheets-Sheet 2 J INVENToRs Lm@ J.' JW

gaaf/Zaad ATTOR YS Aug- 6, 1957 5.1'. sTooTHoFF r-:TAL- 2,801,846

SIGNATURE- GATHERING MACHINE Filed Aug. 18. 1955 l 5 sheets-smet s IN V EN TORIS ATToR evs Aug. 6, 1957 s. T. sTooTHQFF ETAL I 2,801,846

SIGNATURE GATHERING MACHINE Filed Aug. 18. 1955 5 sheets-sheet 4 ,o9 Ho 95 Azz 94, wf 7:15 7

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SIGNATURE GATHERING MACQINE Filed Aug. 1a 1955I '5 sheets-sheet 5 INVENToRs v AT-ronzvs United States Patent SIGNATURE GATHERING MACHINE Stanley T. Stoothol'l, Glen Rock, N. J., and Leo C. Williams, Pearl River, N. Y., assignors, by mesne assignments, to Miehle-Goss-Dexter, Incorporated, a corporation of Delaware Application August 18, 1955, Serial No. 529,279

40 Claims. (C l. 27056) This invention relates to signature gathering machines, and to signature calipering and detecting mechanisms thereof employed to prevent assembling of signature groups containing more or less than the required number of signatures.

One object of the present invention is to provide a signature gathering machine of new and improved construction which is eflicient, dependable and rapid in operation, rugged in structure, employs a minimum of parts, and requires substantially less space for its installation than signature gathering machines of the same general character heretofore known.

Another object of the invention is to provide a signature gathering machine wherein the supply stacks of signatures are arranged in spaced tandem relation, the separation of the signatures from the bottom of said supply stacks is controlled by the operation of a reciprocal carriage disposed beneath said stacks, and the extraction of the separated signatures successively from the supply stacks is effected by gripper units carried by said carriage.

Another object is to provide a signature calipering and detecting mechanism having structural simplicity, being less expensive to manufacture, being easy to adjust, and being accurate and positive in operation.

Another object is to provide a novel signature calipering mechanism which will dependably effect actuation of suitable control means upon variations in the thickness of signatures to the degree of two thicknesses of paper in excess of normal thickness.

Another object is to provide a novel signature calipering and detecting mechanism associated with a signature engaging and transporting gripper in a manner such that the calipering and detecting operations may be advantageously performed by ysaid gripper and the results thereof transmitted to said mechanism, whereby suitable control means will be actuated when plural signatures are simultaneously gripped by said gripper and upon failure of said gripper to engage and seize a signature.

Another object is to provide a novel signature calipering mechanism constructed and associated with a rectilinearly reciprocal signature gripping and transporting unit in a manner such that actuation of suitable control means by said mechanism is directly responsive to the gripping of plural signatures simultaneously by the gripper of said unit and an accompanying rectilinear movement of said unit.

Still another object is to provide a novel signature detecting mechanism constructed and associated with a rectilinearly reciprocal signature gripping and transport-k ing unit in a manner such that suitable control means will be actuated by said mechanism in response to the failure of the gripper of said unit to grip a signature and an accompanying rectilinear movement of said unit, and that actuation of said control means by said mechanism upon said movement of said unit will be prevented in response to the presence of a signature and gripping engagement thereof by `said gripper.

The above and further objects and novel features of the invention will more fully appearfrom the following detailed description when the same is `read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a detinition of the limits of the invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views,

Fig. l is a vertical longitudinal sectional View of a portion of a signature gathering machine embodying signature calipering and detecting mechanisms, all constructed, arranged and operated in accordance with the present invention, certain of the parts having portions thereof broken away for purposes of clearer illustration;

Fig. 2 is a fragmentary side elevational View, partly in section, showing the driving and operating means for said machine;

Fig. 3 is a detail end elevational view, partly in section, looking from the right of Fig. l, showing the reciprocal carriage for the signature gripping units and the operating connections thereto;

Fig. 4 is a detail end elevational View, partly in section, looking from the right of Fig. l, showing the reciprocal carriage and the supporting and guiding means therefor; Fig. 5 is an enlarged detail side elevational view, partly in section, of one of the signature gripping units and associated signature calipering and detecting mechanism, shown in Fig. 1, a portion of one of the parts being broken away for purposes of clearer illustration;

Fig. 6 is an end elevational View, partly in section, of the structures shown in Fig. 5, said view being taken substantially from the position indicated by the line 6-6 of Fig. 5;

Fig. 7 is a vertical longitudinal sectional view taken substantially on the irregular line 7 7 of Fig. 6;

Fig. S is a somewhat diagrammatic view showing the parts of the signature calipering and detecting mechanism in the positions they occupy upon failure of the gripper to seize a signature; p

Fig. 9 is a view similar toFig. 8, but showing the parts of the signature calipering and detecting mechanism in the positions they occupy when plural signatures are simultaneously gripped` by the gripper; and y Fig. l0 is a schematic diagrammatic representation of an electric wiring circuit for the operation and control of the signature gathering machine.

Referring to the drawings, one form of signature caliperingand detecting mechanism constructed and operated in accordance with the present invention is herein illustrated as being embodied in a signature gathering machine of new and improved construction wherein a series of supply stacks of printed and folded sheets referred to as signatures are arranged in spaced tandem` relation, and said signatures which may consist of four pages minimum to sixtyfour pages maximum are simultaneously fed from said stacks by a corresponding seriesof signature feeders including rectilinearly reciprocal gripper units. The fed signatures are then successively assembled flatwise one upon another into groups by a pusher type conveyor for subsequent stitching and/or other binding operations to form complete books, magazines, or the like. it will be understood that the novel signature calipering and detecting mechanism may also be embodied in other signature handling machines, as well as in machines other than signature handling machines, wherein signatures as well as plain sheets of'signature thickness are presented by a gripper unit or units to devices or instrumentalities for action thereon.

The new and improved signature gathering machine `herein illustrated includes in its complete form a plutudinal center line of said machine.

rality of the aforesaid signature feeders arranged in spaced tandem relation, but for the sake of simplicity and brevity in illustrating and describing the present invention, and since all of the feeders are identical in construction, arrangement and operation, only two of said feeders and only those portions of the machine with which the present invention is actually concerned are herein illustrated. The signature feeders chosen for illustration herein are those which are intermediate the first and last feeders of the entire series.

With reference to the drawings, particularly to Fig. l thereof, 15 indicates a portion of the main framework of the signature gathering machine which rests on and may be bolted or otherwise suitably secured to the floor or other machine foundation where said machine is installed. The framework 15 which is of skeleton construction is substantially rectangular or box shaped and is adapted to support all of the signature feeders and other stationary and movable parts of the machine to be hereinafter described. The various movable parts of the machine including the movable parts of the signature feeders are operated from any suitable source of power herein shown as an electric motor-speed reduction drive unit 16 (Fig. 2) which is suitably supported on the framework 15. Electric current is supplied to the motor 17 of the drive unit 16 from any suitable source, and manual starting and stopping of said motor and said unit and all parts of the machine driven thereby is effected by a suitable electrical switch 18 which is connected in the electrical control circuit for said motor, as illustrated in Fig. l and to be hereinafter described in detail.

As will be seen from Fig. l, the two signature feeders illustrated herein and indicated generally at 19 and 20, as well as those, not shown, preceding and succeeding said feeders, are located in spaced tandem relation above and along the length of the framework 15. As herein shown, each signature feeder comprises a pair of transversely spaced upright side plates 21 which are bolted or otherwise suitably secured at their lower ends to the outer surfaces of the framework 15 at the opposite sides thereof. The side plates 21 are connected together by three cross bars 22, 23 and 24 which are bolted or otherwise suitably secured at their opposite ends to said plates. For purposes to appear hereinafter, the cross bar 22 is inclined downwardly and forwardly from the horizontal in the direction of feed of the signatures, the cross bar 23 is turned on its edge and inclined forwardly from the ver- .tical such that it is disposed at right angles to the inclined cross bar 22, and the cross bar 24 is turned on its edge to a substantially vertical position.

Resting on and disposed at the same inclination as the cross bar 22 are two spaced parallel bars 25 and 26 (Figs.

1, and 6) which extend lengthwise of the machine and are symmetrically located at opposite sides of the longi- These bars 25, 26 project at their forward ends a short distance beyond the cross bar 22 and extend rearwardly beyond said cross bar. Except for the last feeder (not shown) of the series which is located at the right-hand end of the machine as viewed in Fig. 1, the bars 25, 26, as will be seen from vFig. l, of the respective feeders extend rearwardly therefrom to the next adjacent feeder and are bolted or otherwise suitably secured at their rear ends to the cross bar 23 of said adjacent feeder. As to the last feeder, the bars 25, 26 thereof are bolted at their rear ends to and supported by an auxiliary cross bar suitably carried by the framework 15.

Each signature feeder includes a hopper for receiving and supporting a supply stack of signatures 27, said hopper comprising a saddle shaped base plate 28 (Fig. 1) which is located centrally of the machine between the feeder side plates 21, a likewise centrally located front abutment plate 29, a likewise centrally located rear abutment strip 30, and two angle type front corner guides 31,

one only of said guides being shown. The base plate 28 terminates short of the front abutment plate 29 so that the front marginal portion of the lowermost signature 27 of the stack is exposed for separation and extracting purposes. The base plate 28 rests on the bars 25 and 26 and, hence, is disposed at the same angle of inclination as said bars so that the signatures 27 tend to slide forwardly by gravity into contact with the front plate 29 and corner guides 31, and will be properly positioned to facilitate accurate separation and extraction thereof from the hopper by separating and extracting means to be hereinafter described. The base plate 28 is bolted to the upper surfaces of the bars 25, 26, the bolts passing through said plate and said bars and being threaded into the cross bar 22. The front `abutment plate 29 is bolted or otherwise suitably secured to the cross bar 24. The rear abutment strip 30 is adjustably secured to the base plate 28, and the corner guides 31 are adjustably clamped to the cross bar 24, to accommodate signatures of different lengths and widths, respectively. The signatures 27 are placed in the hopper with the folded binding edges thereof facing the front abutment plate 29.

In each signature feeder, the exposed marginal portion of the lowermost signature 27 of the supply stack is separated downwardly away from said stack and moved into position for action thereon of gripper type extracting means to be hereinafter described. 1Eer this purpose, each feeder is provided with a suction signature separating device comprising a lever 32 (Fig. l) which is disposed between the bars 25 and 26 adjacent the forward ends thereof and is pivotally mounted as at 33 on said bars for free swinging movement toward and away from the supply stack of signatures 27. The lever 32 is provided at the free forward end thereof with two transversely spaced vand aligned, upwardly facing suction cups 34, one only being shown, for engaging and gripping the lowermost signature 27 at transversely spaced points substantially centrally thereof. The lever 32 is yieldingly urged downwardly away from the signature supply stack by a coil extension spring 35 having one end thereof suitably connected, as at 36, to said lever, and the opposite end suitably connected to the cross bar 22. The extent of downward pivotal movement of the lever 32 by spring 35, and the location of the separated portion of the lowermost signature 27 by the suction cups 34 in proper extracting position are controlled by a stop element 37 which is adjustably secured in said lever and is located to engage the cross bar 22.

The suction devices comprising the levers 32 and suction cups 34 thereon of all of the signature feeders are rocked in unison toward the respective supply stacks of signatures 27 to simultaneously bring said suction cups into gripping engagement with the respective lowermost signatures of said stacks. For this and other purposes to appear hereinafter, there is provided a rectilinearly reciprocal, ladder type carriage, indicated generally at 38 (Figs. l to 4) lwhich is horizontally disposed beneath the signature feeders and extends substantially the entire length of the machine. This carriage 38 comprises a longitudinal square or rectangular bar 39 at one side, a longitudinal round bar 40 at the other side, and a plurality of rungs or cross brackets 41 equally spaced along said bars and bolted or otherwise suitably secured thereto, said rungs being spaced the same as the spacing of the feeders. The carriage 38 is shown in Fig. 1, in the position it occupies with resp-ect to the signature feeders when said carriage is in its extreme retracted or rearward position toward the righthand end of the machine as viewed in said figure, the rungs 41 being so located that with the carriage in said position there will be one of said rungs adjacent each feeder as herein shown, and a further rung or cross bracket (not shown) located rearwardly of the last feeder of the series. The number of rungs or cross brackets 41 employed in the complete machine will, therefore, at least be one in excess of the number of signature feeders present in the complete machine.

The carriage 38 is supported and guided for straightline reciprocating movement by suitable bearing blocks 42 and 43 (Figs. 1 and 4) which are bolted or otherwise suitably secured to the inner surfaces of the side plates 21 of all of the signature feeders and slidably receive the bars 39 and 40, respectively, of said carriage therein. The rungs 41 of carriage 38 beginning with the rearmost rung and ending with the rung adjacent the foremost rung have adjustably secured therein a forwardly projecting abutment element 44 (Figs. l and 5), all of said elements being so located that they are in longitudinal alignment with each other and disposed in the plane of the lower portions of the levers 32 of the respective feeders.

Reciprocating movement is continuously imparted to the carriage 38 from the drive unit 16, and for this purpose the output shaft 45 (Fig. 2) of said unit has fixed thereon a small diameter sprocket 46 around which passes a chain 47 which also passes around and drives a larger diameter sprocket 48. This sprocket 48 is fixed on and drives a short shaft 49 which is journalled in suitable bearings in the framework 15. The shaft 49 has fixed thereon for rotation thereby a crank arm 50 to the free end of which is pivotally connected one end of a link 51. The opposite end of link 51 is pivotally connected to the free end of a downwardly projecting arm 52 which is xed on a shaft 53 that is journalled in suitable bearings in the framework 15 and projects outwardly beyond opposite sides of said framework. This shaft 53 has fixed on the outwardly projecting opposite ends thereof arms 54 which project upwardly from said shaft at opposite sides of the machine and have pivotally connected to the upper free ends thereof the front ends of two horizontal links 55. The links 55 extend rearwardly from the arms 54 and have their rear ends pivotally connected to two journals 56 (Figs. l and 3) which are bolted or otherwise suitably secured to the bars 39 and 40 and to the opposite ends of one of the rungs or cross brackets 41 of the carriage 38 and project outwardly beyond said bars to receive said links. The carriage 38, upon operation of the drive unit 16, will thus be continuously reciprocated by said unit through the described driving connections therefor with the continuously driven shaft 49.

It will thus be apparent that upon movement of the carriage 38 from its extreme retracted position at the right-hand end of the machine to its extreme advanced position at the left-hand end of said machine, as viewed in Fig. 1, the abutment elements 44 on said carriage will simultaneously engage the levers 32 and swing said levers upwardly in unison until the suction cups 34 engage and grip the lowermost signatures 27 of the respective supply stacks. Engagement of the abutment elements 44 with the levers 32 occurs as the carriage 38 approaches the end of its movement in the leftward direction (Fig. l), and engagement of the suction cups 34 under slight upward pressure with the lowermost signatures of the supply stacks occurs at the end of said movement. Upon return movement thereafter of the carriage 38 from its extreme advanced position to its extreme retracted position, the abutment elements 44 simultaneously move away from and out of engagement with the levers 32, whereupon said levers are swung downwardly in unison by the contracting action of the respective springs 35 until the stop elements 37 on said levers engage the bars 22, and the exposed marginal portions of the lowermost signatures Z7 engaged and gripped by the suction cups 34 are simultaneously separated and moved downwardly away from their respective supply stacks land positioned, as shown in Fig. 1, in the path of movement of extracting means to be presently described.

Suitable valve means (not shown) connected with a suitable source of vacuum and with the suction devices controls the making and breaking of vacuum in the suction cups 34 such that vacuum is simultaneously created in all of the suction cups when the levers 32` are moved toward the respective supply stacks of signatures 27, and is simultaneously broken in said cups just prior to or simultaneously with engagement of the separated marginal portions of the lowermost signatures by the extracting means.

Shortly after the marginal portions of the lowermost signatures 27 have been separated from their respective supply stacks as above described, said lowermost signatures are gripped in unison at the separated marginal portions thereof by independent gripper units and completely extracted in unison from said stacks. These gripper units, indicated generally at 57 (Figs. l, 5, 6 and 7) are advantageously mounted on the described carriage 38, whereby straight-line reciprocating movement is irnparted to said units collectively by said carriage to extract and further advance the lowermost signatures 27 from their respective supply stacks, and the grippers of said units, through such movement, are actuated to grip and release said signatures. Specifically, the gripper units 57 are mounted on the rungs or cross brackets 41 of the carriage 38 centrally of said rungs, but it is pointed out that in the complete machine, with the carriage in its extreme retracted or rearward position, as shown in Fig. 1, the gripper units 57 are mounted only on the rungs which are disposed adjacent to and in advance or forwardly of the respective signature feeders, and there is no gripper unit mounted on the rung or cross bracket which is disposed rearwardly of the last feeder. The gripper units 57 are identical in construction, mounting and operation and a description of one of said gripper units will therefore sullice for all of the same.

As herein shown, particularly in Figs. 5, 6 and 7, each gripper unit 57 preferably comprises a main body or bracket 58 which is bolted or otherwise suitably secured to the upper surface of the rung or cross bracket 41 of the carriage 38 and is constructed to provide at opposite sides thereof a laterally off-set, rearwardly projecting, upper gripper jaw 59 formed integrally therewith. The fixed jaws 59 are symmetrically located at opposite sides of the longitudinal center line of the machine and such that they are disposed laterally and outwardly of the suction cups 34 of the respective feeders. Cooperating with the fixed jaws 59 to grip a signature 27 are companion, movable, lower gripper jaws 601, one of which is pinned or otherwise suitably secured to one end of a transverse stub shaft 61, and the other of which is loosely mounted on the other end of said shaft. The loose gripper jaw 60 is held against axial displacement from the A,shaft 61 by any suitable well-known means herein shown as a washer 62 and cotter pin 63. The shaft 61 is journalled in suitable bearings 64 which are formed on and spaced transversely of the bracket 58, said shaft projecting outwardly beyond said bearings to receive the jaws 60. The described mounting of the movable gripper jaws 60 provides for pivotal movement and operation of said jaws independently of each other, whereby accurate firm engagement of each signature 27 at transversely spaced points by both sets of gripper jaws 59, 60 is always assured.

Each movable gripper jaw 60 has pivotally connected thereto at one side of the pivotal axis thereof, as indicated at 65 (Figs. l and 5), one end of a rod 66 which projects forwardly from said jaw and has its opposite end disposed in a suitable elongated clearance opening 67 formed in the bracket 58. Surrounding each rod 66 is a .coil compression spring 68 having one end thereof engaging against a forwardly facing shoulder on said rod and the opposite end engaging against the Hat. face of a halfround shoe 69 which is slidably engaged over the rod and is yieldingly pressed by said spring against the adjacent edge of the opening 67 for said rod in the bracket 58. The shoes 69 on rods 66 allow for rocking up and down movement of said rods. Each movable gripper jaw 60 has formed integrally therewith an actuating arm 70 which projects radially therefrom above the upper surface `of the bracket 58 and the companion jaw 59 on said bracket. The arms 70 of the gripper jaws 60 cooperate` with xed gripper opening and closing cams 71 and 72, respectively, which are located in the path of linear'movement of said arms, there being two of the cams 71 and two of the cams 72 to provide for independent operation of said jaws, as above described.

The cams 71 and 72 correlated to the gripper units 57 are adjustably secured to the bars 25, 26 and 23, respectively, of the respective feeders, the arrangement being such that Vthe cams 7l on the bars 25, 26 of a 'succeeding feeder serve to actuate the gripper jaws 68 of the gripper unit 57 of a preceding feeder. In this connection it is pointed out that in the complete machine the cams 71 for the gripper unit 57 of the first feeder which is located at the left-hand end of the machine (Fig. l) are mounted on a pair of auxiliary bars extending forwardly of said feeder and bolted at their rear ends to the cross bar 23 of said feeder and at their front ends to an auxiliary cross bar suitably carried by the framework 15. The cams 7l and 72 correlated to each gripper unit 57 are so located that Vthe cams 71 are engaged by the arms 70 of the jaws 60 a short distance before the limit of forward movement of the carriage 38 is reached, `and that the cams 72 are engaged by said arms as said carriage approaches the limit of its rearward movement and the gripper jaws 59 and 60 pass respectively above `and below the separated portion of the signature 27 to be gripped thereby. The' gripper units 57 are shown in Fig. l in their rearmost positions with the respective gripper jaws 60 closed and a signature 27 grippedbetween said jaws and the companion jaws 59 of each unit, this showing being representative of lall the gripper units in the complete machine.

It will thusappear that when the carriage 38 with the gripper units 57 thereon is moved to the left (Fig. '1), the signatures 27 gripped by the jaws 59, 68 ofthe respective units will be extracted in unison by said units completely from their respective supply stacks and advanced in like manner until the arms 78 of the jaws 60 engage their respective cams 71. Upon engagement of the arms 7) with the cams 71 and continued movement of the carriage 38 to the left, the jaws 60 will be swung by said cams away from their companion jaws 59 and the springs 68 will be compressed until they have passed the point of maximum compression, whereupon said springs function with a snap action to swing the jaws 6i! farther away from the jaws 59 to fully opened position, such pivotal opening movement of the jaws 60 being i arrested and limited by engagement of said jaws with the rear surfaces of the respective rungs e1, as shown in broken lines in Fig. 7. The cams 71 are so adjusted that the jaws 60 of each and all the gripper units 57 are 'opened simultaneously. Upon opening of the jaws 60 by the cams 71 sufficiently to release the signatures 27 gripped thereby, said signatures are stripped therefrom by rearwardly projecting stripper fingers 73 (Fig. l) and caused to fall upon auxiliary downwardly and rearwardly inclined trays or supports 74. There may be two or more vof the stripper fingers 73 associated with each signature feeder, said lingers being disposed `in the path of movement of the signatures 27 by the gripper units 57 and at opposite sides of the path of movement of said units. The fingers 78 and the tray 74 of each of the feeders beginning with the last feeder and ending with 'the second feeder of the series are suitably secured at their forward ends to the cross bar 22 of the feeder next succeeding the same, and the fingers and tray pertaining to the Vfirst feeder (not shown) are suitably secured 'to the auxiliary cross bar associated with said first feeder. Each of the supports or trays 74 is in the form of a plurality of transversely spaced strips, but may be of lgrid-like one-piece construction, as desired.

After the, signatures 27 have been extracted from the supply stacks, advanced and released by the gripper'units 57, and stripped from said units by the fingers 73v and delivered to the trays 74, as above described, the carriage 38 in continuing its movement to the left (Fig. l) causes the abutment elements 44 thereon to engage and swing the suction devices 32, 34 into gripping engagement with the next lowermost signatures 27 of the supply stack just as said carriage reaches the end of its forward travel. Upon return movement thereafter of the carriage 38 to the right (Fig. l), the suction devices 32,

'34 are first released by the abutment elements 44, whereupon said suction devices function to separate downwardly the marginal portions of the next lowermost signatures of the supply stacks. As the carriage 38 now approaches the end of its return movement, the jaws 59 and 6@ of the respective gripper units 57, being in opened position, pass respectively over and under the separated signature portions and substantially simultaf neously therewith the arms 70 of the jaws 60 engage their respective cams 72, whereupon movement of said jaws toward their companion jaws 59 is initiated. Again this initial movement of the jaws 68 compresses the respective springs 68 and as soon as said jaws have passed the point of maximum compression of said springs which occurs just as or just shortly before the carriage 38 reaches the limit of its return movement, the springs again function with a snap action to continue the movement of said jaws toward the jaws 59 until they are closed Vand have gripped the separated portions of the next lowermost signatures 27 therebetween. At about this time, the carriage 38 is again advanced and the above described'operations are repeated with respect to the next lowerrnost signatures 27 and the signatures next following the same, whereby successive signatures are fed from the supply stacks and delivered in succession to the trays during successive cycles of operation of the machine.

The signatures 27 delivered to the trays 74, as above described, during each cycle of operation of the machine are removed from said trays in unison, deposited upon a suitable table-like support 75, a portion only of which is herein shown, and advanced along said support progressively beneath the successive trays 74. For this purpose, there is provided below the series of trays 74 a conveyor which is associated with the support 75 and like the latter extends substantially the entire length of the machine. The support 75 is formed of a plurality of transversely spaced longitudinal sections suitably supported on the framework 15, and the conveyor comprises two transversely spaced endless chains 76, one only and only a portion thereof being herein shown, which are located centrally of the machine and below the support 75 and rest on and ride along two parallel rails or tracks 77 that are suitably secured to the framework 15. The chains 76 are provided at spaced intervals therealong with pushers 78 which project upwardly from said chains between the sections of the support 75. The pushers 78 are of such height that they extend above the signature receiving and supporting surfaces of the trays 74, and said pushers are spaced the same as the spacing of the signature feeders.

The chains 76 and therewith the pushers 78 are continuously driven and Asuch that said pushers travel in a rearward or rightward direction, as viewed in Fig. l. The chains 76 are driven at a predetermined speed such that for each cycle of operation of the machine, the pushers 78 will be advanced an extent equal to the spacing thereof. This drive for the chains 76 and pushers 78 is taken from the drive unit 16 by suitable sprocket and chain means (not shown) connecting the output shaft 45 of said unit with said conveyor chains.

It will thus appear that through such rearward or rightward movement of the pushers 78 and engagement Vof successive pushers simultaneously or substantially so with the folded binding edges of the signatures 27 o n 9 the successive trays 74, said signatures will be removed by said pushers in unison from said trays edgewise and in the same direction, deposited flatwise upon the support 75 and advanced along the latter progressively beneath the successive trays to the delivery or righthan-d end of the machine. It will also appear that each pusher 78 in travelling from tray to tray during successive cycles of operation of the machine, will remove the signature 27 from each succeeding tray 74 and deposit the same upon the signature 27 previously removed from the next preceding tray, thus assembling the signatures into complete groups, each consisting of one signature from each of the several feeders, and advancing the successive groups toward the final discharge or to the means which transfer said groups to the stitcher or other binding mechlanism.

It is to be noted that the extent of upward pivotal movement of the gripper jaws 60 of each gripper unit S7 toward their companion lixed jaws 59 is variable, such movement being less for a thick signature than it is for a thin signature gripped by and between said jaws, and being more when no signature is gripped by said jaws and the latter make direct contact with each other.

It is important in a machine of the character described, that during the normal operation of the machine a signature and only one signature at a timeV is extracted from each supply stack so that only groups thereof which are complete as to the correct number of signatures are assembled in and discharged from the machine. Accordingly, signature calipering and detecting mechanism of novel construction is provided and associated with 4each of the signature feeders to prevent assembling in the machine of signature groups containing more or less than the correct number of signatures. The novel signature caliper-ing and detecting mechanisms operate independently of each other and they are arranged to caliper the signatures 27 and thereby detect variations in the thicknesses thereof above normal thickness while saidl signatures are gripped by the gripper units 57 and are being extracted from the supply stacks, and to also detect the absence at this time of a signature in gripping engagement by any of said gripper units. When plural signatures 27 are simultaneously gripped and extracted from a supply stack` by any one of the gripper units 57, and when any one of said gripper units fails to grip and extract .a signature 27 from its respective supply stack, the novel calipering and detecing mechanism detecting such abnormal conditions functions to automatically stop the machine and give a visual signal indicating the feeder or station at which the abnormal condition occurred and exists. These novel signature calipering and detecting mechanisms, indicated generally at 80 (Figs. l, 5, 6 and 7), are identical as respects their construction, mounting and operation and a description of one of said mechanisms will therefore be suicient for all of the same.

In the performance of the signature calipering and detecting operations, each signature calipering and detecting mechanism 80 cooperates with the gripper unit 57 of the feeder with which said mechanism is associated. To this end, one of the gripper jaws 60 of the cooperating gripper unit 57 is advantageously utilized as the signature thickness gauging means, as well as the absent signature detecting means, since the Vthickness of the signature 27 gripped by said jaw and its companion jaw 59, as well as the failure of said jaws to grip a signature 27, is reflected in the extent of upward pivotal movement of the jaw 60 to bring the same into gripping engagement with the signature 27 or into direct contact with the jaw 59. Each signature calipering and detecting mechanism St) therefore includes the gripper unit 57 and comprises other elements which are preferably constructed, mounted and operated as follows.

Pinned or otherwise suitably secured to the gripper jaw shaft 61 is a controlling dog or ar'm`81 (Figs.` 'i and 7) which is disposed between the bearings 64 on the gripper body or bracket 58 and extends forwardly and curves downwardly from said shaft. Accordingly, upward pivotal movement of the gripper jaw 60 pinned to the shaft 61 results in downward pivotal movement of the dog 81, and downward pivotal movement of said jaw results in upward pivotal movement of said dog. The dog 81 is so positioned about the shaft 61 with respect to the gripper jaw 60 that when said jaw is fully closed and contacts its companion gripper jaw 59, as shown in full lines in Fig. 7, said dog is disposed in the lowerrnost full line position thereof shown in said figure, and when the jaw 60 is fully opened and contacts the rung 41 of the carriage 38, as shown in broken lines in Fig. 7, the dog 81 is disposed in the uppermost broken line position thereof shown in said ligure. It will thus be apparent that during the normal operation of the machine, the dog 81 will be rocked to its farthest lowermost full line position shown in Fig. 7 each and every time the gripper jaw 60 is fully closed and contacts its companion gripper jaw 59, that said dog will be rocked to its farthest uppermost broken line position shown in said figure each and every time the gripper jaw 6@ is fully opened and contacts the carriage rung 41, that said dog will be rocked to a position intermediate said full and broken line positions each time a signature 27 is gripped by and between the jaws 59 and 60, and that said intermediateposition will vary depending on the thickness of the signature 27 gripped by said jaws.

The free end of thecontrolling dog 81 `is adapted, under certain conditions, to engage and to be engaged by a contact member 82 (Figs. 6 and 7) in the form of a machine screw which is adjustably threaded in a relatively long controlled lever S3 and is locked in adjusted positions by a lock nut 84. This lever 33 is horizontally disposed below the dog 81 and between the bearing portions 64 of the gripper bracket S8 and is pivotally mounted at the rear end thereof on a pin 85 which is journalled in suitable aligned bearings :formed in said bearing portions. The lever 83 projects forwardly below and beyond the free end of the dog S1 and between the gripper bracket 58 and the carriage rung 41, said bracket and said rung being formed with suitable clearance spaces in their lower and upper surfaces, respectively, to receive said lever and enable pivotal up and down movement thereof about the pivot 85. The lever 33 is yieldingly urge-d toward the dog 31 by suitable biasing means, such as a coil compression spring 86 having one end portion thereof seated in a suitable socket formed in the carriage rung 41 and the opposite end portion seated in a suitable socket formed in said lever.

The lever 83 has pivotally connected to the forward `free end thereof, as at 37, a second controlling member in the form of a finger 88 which projects upwardly from said lever beyond the upper surface of the gripper bracket 58 through a suitable clearance space formed in said bracket. The finger 88 is preferably, but not necessarily, provided at the upper end thereof with a forwardly facing, hardened steel, wear resisting tip 89, for a purpose to appear hereinafter. A leaf spring 90 is suitably secured forwardly of the finger 8S to the carriage rung 41 and engaged with said linger so as to yieldingly press the latter rearwardly against a smooth inclined surface 91 formed on a portion 92 of the gripper bracket 58, said spring and said surface cooperating to guide the iinger `S8 for substantially straight-line up and down movement by the lever 83, and said bracket portion serving to hold said finger against rearward pivotal movement. By virtue of the proportional lengths of the controlling `dog 81 and the controlled lever 83, variations in the thickness of the signatures 27 and in the extent of upward pivotal movement of the gripper jaw 60 `are ,said lever reaches the bracket portion 921.

thus multiplied at the free forward end of said lever and transmitted to the controlling finger 88. Also, by virtue of the described mounting of the elements S1, 83 and 88 on the gripper bracket 58, said elements travel with the gripper unit 57 during reciprocation thereof.

It will thus appear that with the construction thus far described, with the contact screw 82 adjusted relative to the controlled lever 83 to the position thereof shown in Fig. 7, when the controlling dog 81 occupies the full line position thereof shown in said figure through upward pivotal movement of the gripper jaw its maximum extent into contact with its companion gripper jaw 59 due to the absence of a signature 27 in gripping position or the failure of said jaws to grip a signature, the controlled lever 83 will, through engagement of the dog 81 with the contact screw 82 be depressed by said dog a predetermined extent to the full line position thereof shown in Fig. 7. Under these conditions, the controlling finger will be retracted by the lever 83 relative to the gripper bracket 58 an extent commensurate with the extent of downward movement of the free end of said lever, thus locating the upper end of said finger at the low level full line position thereof, shown in Fig. 7, above said bracket, for a purpose to be hereinafter explained. The adjustable contact screw 82 provides for accurately locating the controlling finger 88 in the described low level position, and for vertically adjusting said linger to other positions, as hereinafter explained.

When a single signature 27 is gripped by the jaws 59, 60,

or plural signatures 27 are simultaneously gripped by said jaws, resulting in each case in downward pivotal movement of reduced extent of the controlling dog 81, said dog .upwardly about the pivot by the expanding action of the spring 86 until the contact screw 82 engages the dog 81, or said lever engages the underside of the bracket portion 92, as the case may be depending on the position of said dog. For all single signatures 27 of all thicknesses that may be handled, the described upward movement of the lever 83 is arrested and limited by the dog 81 before For plural signatures 27 within a certain range of thicknesses, the described upward movement of the lever 83 is also arrested and limited by the dog 81 before said lever reaches the bracket portion 92, but for plural signatures 27 above said thickness range the described upward movement of .said lever is arrested and limited by said bracket portion before it reaches said dog. Upon the described upward movement of the lever 83 by the spring S6, the controlling finger S8 will be projected by said lever relative to the gripper bracket 58 an extent commensurate with the extent of upward movement of the free end of said lever, thus locating the upper end of said linger at a higher level above said bracket when a single signature 27 is normally gripped by the jaws 59, 60, and at a still higher level whenever plural signatures 27 are simultaneously gripped by said jaws.

In Fig. 7 of the drawings, the above described higher levels of the projected controlling linger 88 are represented 'when signatures 27 of a thickness less than .O50 of an inch are handled and a single signature of such thickness is normally gripped by the jaws 59, 60, the described A 'level of the iingervSS will be correspondingly lower under the control ofthe controlling dog 81, and whenever plural signatures of such thickness are simultaneously gripped by said jaws, the described B level of said nger will in some instances be correspondingly lower under the control of saiddog, and in other instances will be attained under the control of the bracket portion 9?. since engagement of the controlled lever 83 with said bracket portion occurs when the nger 88 reaches said B level.

The controlling finger 8S, through linear movement thereof with the gripper unit 57 in the signature extracting direction, is adapted to engage and actuate novel control means whenever an abnormal condition in the feeding of the signatures 27 is detected by the gripper jaw 60 of said gripper unit, said control means forming a component part of the novel signature calipering and detecting mechanism 80 and serving to stop the machine and effect operation of a suitable visual signal indicating the feeder or station at which the abnormal condition occurred. As herein shown, the novel control means of each signature calipering and detecting mechanism 80 associated with each signature feeder is located forwardly of the feeder and between the end limits of reciprocating movement of the gripper unit 57 pertaining to said feeder, each of said control means comprising the following elements preferably constructed, mounted and operated as follows.

Engaged over and straddling both of the longitudinal bars 25 and 26 extending forwardly of the feeder is an inverted U-shaped support bracket 93 (Figs. l, 5, 6 and 7) which is bolted or otherwise suitably secured at the lower end thereof to the outer surfaces of said bars and projects upwardly therefrom. Disposed within and carried by the ybracket 93 is a smaller inverted U-shaped bracket 94 consisting of two-parallel side plates 9S and a top plate 96 which are secured together by machine screws 97 extending through suitable clearance holes in said side plates and threaded into said top plate. The side plates are further held in spaced parallel relation by annular spacers 98 and 99, and machine screws 100 which pass through suitable clearance openings in said plates and said spacers and have threaded thereon jam nuts 101. The .inner bracket 94 is positioned centrally between the side walls of the outer bracket 93 and is maintained in said position by suitable annular spacers 102 disposed betweensaid brackets at opposite sides thereof. These spacers 102 are engaged over sleeves 103 which project laterally in lopposite directions from the inner bracket 94 beyond the outer bracket 93 through suitable elongated vertical openings 104 formed in the side walls of said outer bracket. The sleeves 103 are rmly pressed at theirinner ends against the side plates 95 of the inner bracket 94 by machine screws 105 which are passed through said sleeves and threaded into said plates. Surrounding the outer ,portions of the sleeves 103 are coil compression springs against the outer smooth surfaces of the side walls of the outer bracket 93. The outer ends of the springs 106 are engaged under strong tension against washers 108 which are engaged over the screws 105 and located between the outer ends of the sleeves 103 and the heads of said screws. It will thus be apparent that the described mounting of the inner bracket 94 on the outer bracket 93 provides for vertical adjustment of said inner bracket relative t0 said outer bracket within the range of the length of the slotted openings 104 in the outer bracket, and that the inner bracket will be held in any position of vertical adjustment thereof by the spring-pressed friction discs 107.

The top plate 96 of the inner bracket 94 has suitably secured therein the lower end of a stud 109 which extends upwardly through a suitable clearance opening formed in the top wall of the'outer bracket 93. The upper end portion of the stud 109 is externally threaded and has threaded thereon an adjustable wing nut 110` which is engaged with the bracket 93. Surrounding the stud 109 is a coil compression spring 111 having one end thereof engaging against the top plate 36 of the inner bracket 94 and the opposite end engaging against the adjacent top wall of the outer bracket 93. The wing nut 110 and spring 111, through rotation of said nut in opposite directions, provide for raising and lowering the inner bracket 94 and all parts carried thereby to be presently described, as a unit relative to the outer bracket 93 for purposes to be hereinafter described. The spring 111 and nut 110 also cooperate to steady the inner bracket 94 and to respectively resist upward displacement of said bracket and hold the same against downward displacement.

Disposed within the inner bracket 94 and spanning the distance between the side plates 95 of said bracket is a block 112 (Figs. 6 and 7) which is pivotally mounted on the spacer 99 and has riveted or otherwise suitably secured thereto a slightly bowed, thin, spring steel blade 113 which projects downwardly from said block between and below the bars V25 and 26 for engagement by the controlling linger S8, as hereinafter described. This blade 113, in the normal position thereof shown in Fig. 7, is adapted to releasably hold an arm 114 in the raised angular position thereof shown in said ligure, said arm being pivotally mounted at its rear end on the spacer 98 and spanning the distance between the side plates 95 of the inner bracket 94. The arm 114 is formed at the bottom thereof with a downwardly facing shoulder 115 for abutting engagement with the upper edge of the blade 113, a depending blade-confining lip 116 forwardly of said shoulder, and an upwardly inclined blade-camming surface 117 rearwardly of said shoulder. The arm 114 is yieldingly urged downwardly by suitable biasing means, such as a coil extension spring 118 having one end thereof connected to a pin 119 secured in the bar 26, and the opposite end connected to a pin 121i secured in said arm and projecting forwardly therefrom beyond the outer bracket 93. Secured in any suitable manner to the upper surface of the arm 114 is a spring clip 121 within which is yieldingly clamped a mercury switch 122, the same being disposed in parallel relation to said surface so as to assume the same angle of inclination as said arm. This switch 122 is connected in the electrical control circuit for the driving motor 17, as illustrated in Fig. and to be hereinafter described in detail.

Disposed within the outer bracket 93 and spanning the distance between the side walls of said bracket is a bellcrank 123 (Figs. 6 and 7) which is pivotally mounted on a pin 124 suitablycarried by said walls. This bell-crank 123 has suitably secured therein adjacent the bottom thereof a forwardly projecting eyelet 125 which is located centrally between the opposite ends of said bell-crank. Loosely carried by the eyelet 125 for free swinging movement toward and away from the blade 113 is a second slightly bowed, thin, spring steel blade 126 which projects downwardly from said eyelet in back of the blade 113 between and below the bars 2S and 26 for engagement by the controlling finger 8S, as hereinafter described. This blade 126, in the normal position of the bell-crank 123 shown in Fig. 7, rests by gravity against a stop pin 127 which is suitably secured in the bar 25 and projects inwardly from said bar, said pin being so located that when the arm 114 is held in its normal raised angular position by the blade 113, the blade 126 just contacts or just clears the lower tip of the blade 113.

Pivotally connected, as at 128, to the bell-crank 123 at the top and centrally between the ends thereof is the front end of a connecting link 129 (Figs. 6 and 7) which extends rearwardly from said bell-crank and is pivotally connected at its rear end to a forwardly offset loop 130 formed in and located centrally of the cross bar 131 of an inverted U-shaped pendulum 132. The link 129 and pendulum 132 are formed of suitable light weight material, such as small diameter music or spring wire, and said pendulum is loosely carried by eyelets 133 for free swing-` ing movement toward and away from the blades 113 and 126. The eyelets 133 receive the cross bar 131 of the pendulum 132 therein and are located close to the vertical legs of said pendulum and secured in any suitable manner in the feeder cross bar 23. The pendulum 132 in the normal position thereof shown in Fig. 7, extends downwardly from the eyelets 133 on opposite sides of the path of movement of the gripper unit 57, and the length of said pendulum is so chosen that the lower ends of the vertical legs thereof are disposed below the plane of the bite of the gripper jaws 59 and 60 of said gripper unit. The pendulum 132 is gravity biased by the weight of the bellcrank 123 and parts carried thereby toward the feeder cross bar 23 and into normal engagement with an adjustable abutment in the form of a machine screw 134 which is threaded into said cross bar and is locked in adjusted positions by a lock nut 135. The abutment screw 134, through rotation thereof in opposite directions and engagement with the pendulum 132, provides for vertical adjustment of the blade 126 relative to the blade 113, the curvature of the blade 126 being so chosen that when said blade is so adjusted it will not impart any movement to the blade 113 to disengage the same from the arm 114.

Referring now to the electrical control circuit illustrated in Fig. l0, which may be and preferably is used in Controlling the operation of the machine in lieu of other circuits which will accomplish the same result, the motor 17 is of the three-phase type supplied with electrical current from any suitable source through lead wires 136, 137 and 138. Lead wire 136 is connected by a wire 139 with one terminal of the manually operated, main motor starting and stopping switch 18 of any suitable conventional type which when once actuated to start the motor 17 remains in actuated position and requires a second actuation to stop said motor. The other terminal of switch 18 is connected by a wire 141 with a coil 142 of a magnetic switch 143. The coil 142, in turn, is connected to the lead wire 137 by wires 144 and 145 having interposed between the same the various mercury switches 122 of the signature calipering and detecting mechanisms dit employed in the machine, there being only two of said mercury switches shown in the illustrated circuit. The wire 144 connected to the coil 142 is connected to the rst terminal of the rst mercury switch 122, the wire 145 connected with the lead wire 137 is connected to the second terminal of the last mercury switch 122, and the mercury switches 122 are connected in series by wires 146 connecting the second terminal of a preceding mercury switch and the rst terminal of a succeeding mercury switch.

`It will thus be apparent that when the switch 18 is closed, and each of the mercury switches occupies the normal raised angular position thereof shown in Fig. 7, causing the mercury therein to flow to circuit closing position, current will flow from lead wire 136 through wire 139, switch 18, wire 141, coil 142, wire 144, mercury switches 122 and wires 146 and 145 to the lead wire 137. Thereupon, the coil 142 will be energized and actuate the switch 143 to close the latter into contact with terminals 147, 148 and 149 of lead wires 136, 137 and 138, respectively. Closing of the switch 143 starts the motor 17 which receives current from the lead wire-s 136, 137 and 138 through wires 150, 151 and 152 which are connected with said switch and with said motor. The machine will now continue to operate to feed and assemble signatures 27 until the switch 18 is again actuated to open the same, or any one of the mercury switches 122 is released to drop about the pivot point or spacer 93 to a lowered angular position causing the mercury therein to ilow away from the contacts of said switch. Under either of these conditions, the previously described current for energizing the coil 142 will be broken causing said coil to be deenergized, thus opening the switch 143 and stopping the motor 17.

It will also be apparent that when any one of the mercury switches 122 is released to drop and thereby break the circuit to the coil 142 as above described, the motor 17 may again be thereafter started by simply resetting the released mercury switch 122 to its original raised angular position shown in Fig. 7, thus again completing the circuit to said coil.

The visual signalling means previously referred to is preferably in the form of an incandescent lamp 153 (Fig. l) which is suitably mounted at a convenient point on or near each signature feeder, herein shown as on and at the top of one of the side plates 21 of said feeder. With a slight change in the described circuit, solenoid operated flags may be employed in lieu of the lamps 153, if desired.

.As shown in Fig. l0, the lamps 153 are arranged in parallel with the respective mercury switches 122, and said lamps are connected with the lead wires 136 and 137 by wires 154 and 155 which, in the case of the first lamp, are connected to the wires 144 and 146, respectively, in the case of the last lamp, are connected to the wires 146 and 145, respectively, and in the case of the intermediate lamps, are connected to the wires 146 and 146, respectively, leading from adjacent switches 122. It will thus be apparent that by the described circuit arrangement of the lamps 153, when any one of the mercury switches 122 is released to open the same, as above described, the current will ow through the lamp 153 associated with the released and opened mercury switch and,` hence, said lamp will become energized and serve as a signal to the operator, the resistance introduced at this time by said lamp in the circuit to the coil 142 being so great that the flow of current to said coil is insuliicient to enable the same to maintain the switch 143 in closed condition, with the result that said switch will be opened and the motor 17 `will be stopped. When the mercury switches 122 are closed, practically no resistance is created in the circuit by said switches and, hence, insufcient current passes 4 through the lamps 153 to illuminate the same.

As hereinbefore described, the gripper jaws 60 of each gripper unit 57 are opened at a predetermined point along the path of forward movement of said gripper unit, and

. said jaws remain open for substantially the full extent of the return or rearward movement of said gripper unit. With the construction thus far described, the controlling finger 88 will, during the rearward movement of the gripper unit 57, be disposed in its uppermost broken line B level position shown in Fig. 7 and, hence, would strike the blades 113 and 126 and possibly bend or otherwise damage the same. In order to avoid any damage to the blades 1113 and 126 by the controlling linger 88 and unnecessary forward deliection of said finger through engagement thereof with said blades, the linger is retracted to its lowermost broken line position shown in Fig. 7 iinmediately upon opening of the gripper jaws 6i) and held in such retracted position until said jaws are again closed which occurs near the end of the return movement of the gripper unit, as previously described.

For this purpose, the controlling dog 81 and the controlled lever 83 have associated therewith a latch linger 156 (Fig. 7) which is pivotally mounted intermediate its ends on a pin 157 which is suitably mounted in the gripper bracket 58. When the gripper jaws oil are closed, the

i latch linger 156 occupies the angular full line position thereof shown in Fig. 7 wherein it will be noted that the lower end of said linger is spaced clear of the controlled lever 83 to enable upward pivotal movement of said lever, and that the upper end portion of said nger is disposed in the path of upward pivotal movement of the controlling dog 81. Accordingly, when the dog 81 is rocked upwardly to its broken line position shown in Fig. 7 in response to the full opening of the gripper jaws 65, the latch finger 156, through engagement thereof by said dog, will `be rocked in a counter-clockwise direction to 4 the broken line position thereof and held in said position,

The controlled lever 83 will thus be depressed by the latch finger 156 to its lowermost broken line position shown in Fig. 7 immediately upon opening of the gripper jaws 60, and the controlling nger 88, in turn, will be retracted by said lever to the broken line lowermost position thereof such that the upper end of said controlling linger clears the lower tips of the blades 113 and 126 and, hence, will not strike said blades during the return movement of the gripper unit 57. The latch linger 155 is so arranged and constructed, as shown in Fig. 7, that when the dog 81 is rocked downwardly from the broken line position thereof in response to the closing of the gripper jaws 60, thus releasing said latch linger, the latter is no longer effective to hold the controlled lever 83 and is free to swing in a clockwise direction under the upward pressure of said lever thereon applied by the expanding action of the spring 86.

ln the initial make-ready of the described machine for a given job, each signature calipering and detecting mechanism 84) is independently adjusted as follows in combination with the gripper unit 57 with which it cooperates. With the gripper unit 57 positioned directly below the blades 113 and 126, and with the jaws 6) of said gripper unit fully opened, as shown in broken lines in Fig. 7, at which time the controlling dog 81 is disposed in its uppermost broken line position shown in said ligure, the blade 126 is lirst vertically adjusted by means of the abutment screw 134 until the lower tip of said blade just clears the top of said dog. When this adjustment has been made, the blade will occupy the position thereof shown in Fig. 7, thus permitting return movement of the gripper unit 57 without the controlling dog 81 striking the blade 126. The gripper jaws 611 are now fully closed into contact with their companion jaws 50, and the controlling linger 83 is then vertically adjusted by means of the contact screw 82 until the upper end thereof projects above the lower tip of the blade 126 a slight distance, for example, approximately .015 of an inch. When this ad justment has been made, the controlling linger 88 will occupy the full line position thereof shown in Fig. 7 on the forward stroke of the gripper unit 57 with the jaws Gti thereof fully closed and contacting the companion jaws 59 and, hence, said linger being in said position will engage and swing the blade 126 about its pivot point 125 in a clockwise direction, as viewed in Fig. 7.

One only of the signatures 27 to be handled is next taken `from the supply stack thereof and inserted between the closed gripper jaws 59 and 60. This will undoubtedly cause the controlling linger 88 to be projected to a position above the full line position thereof shown in Fig. 7 depending on the thickness of the single signature 27 inserted between and gripped by the gripper jaws 59 and 60. For signatures 27 which are approximately .050 of an inch in thickness, the controlling linger 8S will be projected to the broken line A level position thereof shown in Fig. 7, and for signatures of a thickness less than .050 of an inch, .said linger will be projected to a correspondingly lower position. With the controlling linger 88 thus projected and positioned, the blade 113, by means of the wing nut 11), is next vertically adjusted relative to the blade 126 until the lower tip thereof just clears the upper end of said nger. It is pointed out that when signatures of a thickness of approximately .075 of an inch and over are handled and a ,single signature of such thickness is gripped by and between the jaws 59, 60 of the gripper unit 57, the controlling linger 88 will be projected to its broken line B level position shown in Fig. 7, its maximum extent allowed by the gripper bracket portion 92, but before running these signatures, the controlling linger is retracted by means of the Contact screw 82 to substantially the broken line A level position thereof, and the blade 113 is vertically adjusted by means of the wing nut 110 until the lower tip of said blade just clears the upper end of said controlling linger.

With all of the above described adjustments made, it will thus be apparent that during the operation of the machine, when all of the gripper units 57 have a single signature 27 gripped by and between the jaws 59, 60 thereof on the forward movement of said units, the signatures will engage and swing the pendulums 132 of the calipering and detecting mechanisms 8l) in a clockwise direction, as diagrammatically shown in Fig. 9, and thereby raise the respective blades 126 clear out of the path of linear movement of the projected controlling lingers S8, and said controlling lingers will not be projected high enough to engage and actuate the respective blades 113. Accordingly, none `of the mercury switches 122 will be tripped or actuated and the normal operation of themachine and assembling of signatures will proceed without interruption as long as each gripper unit 57 on each forward stroke thereof has a single signature 27 gripped by and between the jaws 59, 60 thereof.

Let it now be assumed that the gripper jaws 59, 60 of at least one of the gripper units 57 have, for some reason, failed to grip a signature 27, resulting in full closing of the jaws 60 and contact of the same with their companion jaws 59, the blade 126, on the following forward stroke of the gripper unit, will not be raised clear of the retracted, but still projecting, controlling finger 88 due to the absence of a signature between the gripper jaws and, hence, said controlling finger will engage the lower end of said blade and swing it forwardly or in clockwise direction, and said blade, in turn, will engage and swing the blade 113 in the same direction, thus moving the upper end portion of the latter blade out of supporting engagement with the shoulder 115 on the arm 114,`all as diagrammatically shown in full lines in Fig. 8. Thereupon, the arm 114, being released by the blade 113, is swung downwardly about the pivot point 98 by the spring 118 to a lower angular position shown in broken lines in Fig. 8, limited through engagement of said arm with the block 112, and the mercury in the switch 122 on said arm Will flow in the opposite direction to break the electric circuit and thereby stop the motor 17 and the machine. At the same time that the circuit to the motor 17 is broken through opening of the mercury switch 122, the lamp 153 associated with said switch is illuminated, thus giving a Visual signal to the operator as to the feeder or station at which the abnormal condition occurred. When the arm 114 is swung downwardly by the action of the spring 118, the cam surface 117 on said arm operates to cam the blade 113 away from the blade 126, as shown in broken lines in Fig. 8, whereby the blade 113 is gravity biased toward the lip 115 on the arm 114. In this manner, the return movement of the blade 113 and engagement thereof with the shoulder 115 on the arm 114 is assured when, in the resetting of the calipering mechanism 80 after the abnormal condition has been rectified by introducing the missing signature 27 between the closed gripper jaws 59, 60, said arm is raised slightly beyond its original position, shown in Fig. 7, by the operator by means of the pin 120. The introduction of the missing` signature between the closed gripper jaws 59, 60 raises the blade 126 out of engagement with the controlling :linger 88 thus permitting said blade to return by gravity to its original position in engagement with the stop pin 127. Resetting of the arm 114 again closes the mercury switch 122, whereupon the motor 17 is again started and the lamp 153 is extinguished.

Let `it now be assumed that plural signatures 27 are simultaneously gripped by and between the jaws 59, 60 of at least one of the gripper units 57, resulting in increased upward movement of the controlling finger 88 beyond the position it would occupy when normally a single signature is gripped by said jaws. Under these conditions, and as diagrammatically shown in Fig. 9, the blade 126 will be raised clear of the projected controlling finger .8S through forward movement of the plural signatures and engagement thereof with the pendulum 132, and said controlling linger through continued forward movement thereof with the gripper unit 57 will directly engage the blade 113 and swing the same forwardly out of supporting engagement with the arm 114. The arm 114, being thus released by the blade 113, is then swung downwardly by the spring 113 to its lower angular position shown in broken lines in Fig. 8, whereupon the mercury switch 122 on said arrn `is opened to break the electric circuit and thereby cause stoppage of the motor 17' and the machine, and the lamp 153 associated with said switch is illuminated. When the abnormal condition has been corrected through removal of all but one of the plural signatures from between the gripper jaws 59, 6), resulting in retraction of the controlling iinger 88 to its normal single signature position clear of the blade 113, the motor 17 and the machine may again be started by lifting the arm 114 high enough to allow the blade 113 to swing by gravity to its original position against the lip 116 and beneath the shoulder 115 on said arm. This again closes the mercury switch 122 and completes the electric circuit to the motor 17. Upon closing of the mercury switch 122, the lamp 153 associated with said switch is extinguished. v

The operation of the machine, as well as the operation of the signature calipering and detecting mechanism, constructed in accordance with the present invention will be clearly understood'from the foregoing description, and while said description and the accompanying drawings set forth with more or less particularity one embodiment of the invention,` it is to be expressly understood that said invention is not limited to said embodiment. Various changes may be made therein, particularly in the design and `arrangement of the parts illustrated,I as well as in the mode of operation and manner of use, without departing from the spirit and scope of the invention, as will now be clear to those skilled in the art. The calipering and detecting mechanism may be embodied with equal advantages in a rotary type of gripper carrier and also in an oscillating or swing-arm type of gripper carrier, and while said mechanism is especially valuable in a signature gathering machine, it is readily adaptable to other machines handling sheet material.

What is claimed is:

l. In a gathering machine for signatures or sheets, the combination of a plurality of hoppers arranged in spaced tandem relation, each to receive therein a supply stack of the signatures or sheets, an operable suction device associated with `each hopper for separating downwardly a transverse edge portion of the lowermost signature or sheet of the supply stack, a reciprocal ladder type carriage disposed directly below and extending along said hoppers, said carriage comprising longitudinal bars at opposite sides thereof, and a series of longitudinally spaced `cross-rungs connecting said bars, the number of said rungs being at least one in excess of the number of said hoppers and the spacing of said rungs being the same as the spacing of said hoppers, means for reciprocating said carriage, abutment means on certain of said rungs and engageable by the operation of said carriage with the suction devices for moving the latter upwardly into gripping engagement with the lowermost signatures or sheets of the supply stacks as said carriage reaches the end of its travel in `one direction, biasing means operably connected to said suction devices for moving the latter downwardly as `said carriage travels in the other direction and said abutment means move out of engagement with said suction devices, and grippers wholly mounted on certain of said rungs and each comprising a fixed jaw and a companion jaw operable toward said fixed jaw to grip the separated portions of the lowermost signatures or sheets as said carriage reaches the end of its travel in saidsecond-named direction, extract said signatures or sheets from said supply stacks as said carriage travels in said rst-named direction, and release said signatures or sheets at spaced predetermined points along the path of movement thereof in said first-named direction. i

2. Apparatus as dened in claim l, comprising stripper asonsfi'e means disposed at said points and in the path of movement of the signatures or sheets so as to be engaged by tlie leading edges of said signatures or sheets for stripping the same from said grippers when released thereby.

3. Apparatus as defined in claim 1, comprising trays at said points and disposed directly belo-w said carriage for receiving iiatwise the signatures or sheets released by said grippers, a continuously driven endless conveyor disposed directly below and extending along said trays, and pusher means carried by said conveyor and spaced at intervals therealong and projecting through said`trays for removing the signatures or sheets edgewise therefrom and advancing the same progressively beneath the successive trays.

4. Apparatus as defined in claim 3, wherein said conveyor is so driven that the upper active reach thereof travels in a direction the opposite to the travel of the grippers in extracting the signatures or sheets from the supply stacks.

5. Apparatus as defined in claim 3, wherein the spacing of the pusher means is the same as the spacing of the hoppers, and the conveyor is so driven that for each cycle of operation of the machine it is advanced the extent yof such spacing.

6. .In a gathering machine for signatures or sheets, the combination of a series of hoppers arranged in spaced tandem relation, each to receive therein a supply stack of the signatures or sheets, a pivotal suction device associated with each hopper for separating downwardly a transverse edge portion of the lowermost signature or sheet of the supply stack, a reciprocal ladder type carriage disposed directly beneath and extending along said hoppers, said carriage comprising longitudinal bars at opposite sides thereof, and a series of longitudinally spaced cross-rungs connecting said bars, the number of said rungs being at least one in excess of the number of said hoppers and the spacing of said rungs being the same as the spacing of said hoppers, means for imparting rectilinear forward and return movements to said carriage, abutment means on certain of said rungs and engageable by the operation of said carriage with the suction devices for swinging the latter in unison upwardly into gripping engagement with the lowermost signatures or sheets of the supply stacks as said carriage reaches the end of its forward travel, spring means operably connected to said suction devices for swinging the latter downwardly in unison away from the supply stacks as said abutment means move out of engagement with said suction devices on the return travel of said carriage, gripper units on certain of said rungs and reciprocal with said carriage, each gripper unit cornprising a pivotal jaw, a companion fixed jaw, and spring operated means connected to said pivotal jaw for rocking the latter toward and away from said iixed jaw to closed and open positions, respectively, and for yieldingly holding said pivotal jaw in said positions, the jaws of the gripper units being open during the return travel of said carriage so as to receive therebetween the separated portions of the lowermost signatures or sheets as said carriage approaches the end of its return travel, fixed cam means arranged t-o initiate the closing of the pivotal jaws by the spring operated means in unison on the separated portions of the lowermost signatures or sheets as said carriage reaches the end of its return travel, whereby said signatures or sheets are completely extracted in unison from the supply stacks on the subsequent forward travel of said carriage, and other fixed cam means arranged intermediate the end limits yof forward travel of said carriage to initiate the opening of said pivotal jaws in unison by said spring operated means and release of the extracted signatures or sheets by said jaws at predetermined points along the path of forward travel thereof.

7. Apparatus as defined in claim 6, comprising trays at said points and disposed directly beneath said carriage for receiving atwise through lthe spaces between said rungs the signatures or sheets released by the gripper units, an endless conveyor disposed directly beneath and extending along said trays, and upstanding pushers carried by and spaced along said conveyor and projecting through said trays for removing the signatures or sheets edgewise from said trays and advancing the same progressively beneath the successive trays, the spacing of said pushers being the same as the spacing of said hoppers, Aand said conveyor being driven continuously and such that the upper active reach thereof travels in the direction of the return travel of said carriage and that said pushers are advanced the extent of said spacing for each cycle of operation of the machine.

8. Apparatus as deined in claim 7, comprising stripper members disposed at said points and in the path of forward travel of the signatures or sheets for stripping the same from the gripper units when released thereby for delivery to said trays.

9. Apparatus as dened in claim 6, comprising operable control means associated with each hopper and located between the end limits of reciprocating movement of the gripper unit correlated to said hopper, means responsive to the operation of said control means for a desired control function such as eifecting stopping of the machine, and for each gripper unit a controlling member reciprocal therewith and operable to engage and actuate said control means by the forward travel of said carriage when during such travel plural signatures or sheets are simultaneously present between and gripped by the jaws of said gripper unit.

10. Apparatus as detined in claim 6, comprising operable control means associated with each hopper and located between the end limits of reciprocating movement of the gripper unit correlated to said hopper, means responsive to the operation of said control means for effecting a desired control function such as stopping of the machine, and for each gripper unit a controlling member reciprocal therewith and operable lto engage and actuate said control means by the forward travel of said carriage when during such travel no signature or sheet is present between and gripped by the jaws of said gripper unit.

1l. Apparatus as defined in claim 6, comprising operable control means associated with each hopper and located between the end limits of reciprocating movement of the gripper unit correlated to said hopper, means responsive to the operation of said control means for effecting a desired control function such as stopping of the machine, and for each gripper unit an operable controlling member reciprocal therewith for engaging and actuating said control means bythe forward travel of said carriage, and operable means under the control of the pivotal jaw of said gripper unit and responsive to the closing movement of said jaw for operating said controlling member and positioning the Isaine according to the extent of said jaw movement, whereby engagement and actuation of said control means by said controlling member is avoided when only a single signature or sheet is gripped by said gripper unit, and such engagement and actuation occurs when plural signatures or sheets are simultaneously gripped by said gripper unit and when no signature or sheet is gripped by said gripper unit.

12. Apparatus as dened in claim 6, comprising operable control means associated with each hopper and located between the end limits of reciprocating movement of the gripper unit correlated to said hopper, said control means including a movable element, means operable in response to the actuation of said movable element to effect a desired control action of the machine, and for each gripper unit a rst controlling member reciprocal therewith and arranged to be projected relative thereto exteriorly thereof so as to engage and actuate said movable element by the forward travel of said gripper unit, means operably connected to said controlling member for projecting the Same, and a second controlling member connected to and operated by the pivotal jaw of said gripper unit through movement thereof to closed position for controlling the operation of said last-named means and for determining the projected position of said first controlling member according to the thickness of the signature or sheet being gripped by said gripper unit, whereby when only a single signature or sheet is gripped by said gripper unit said lirst controlling member in its resultant projected position will fail to engage said movable element, and when plural signatures or sheets are simultaneously gripped by said gripper unit said first controlling member in its resultant projected position will engage and actuate said movable element.

13. Apparatus as defined in claim 12, comprising latch means mounted on and reciprocal with said gripper unit and operable to hold said first controlling member in retracted position clear of said movable element during the return travel of said gripper unit.

14. Apparatus as defined in `claim 13 wherein said latch means is operated by said second controlling member in response to the movement of the pivotal gripper jaw by the spring operated means to open position.

15. Apparatus as defined in claim 6, comprising operable control means including a movable element associated with each hopper and located between the end limits of reciprocating movement of the gripper unit correlated to said hopper, Said movable element being mounted for movement to an inoperative position, means responsive to the actuation of said movable element for `causing a desired control action of the machine, and for each gripper unit a controlling member reciprocal therewith and adapted to engage and actuate said movable element by the forward travel of said gripper unit, and means operably connected to said movable element and actuated by the signature or sheet gripped by said gripper unit for moving said movable element to its inoperative position whereby engagement thereof by said controlling member is avoided.

16. Apparatus as defined in claim 6, comprising operable control means associated with each hopper and located between the end limits of reciprocating movement of the gripper unit correlated to said hopper, said control means comprising first and second operable elements arranged for operation of said first element independently of said second element and by said second element, and means responsive to the operation of said first element to stop the machine, and for each gripper unit an operable controlling member reciprocal therewith for engaging and actuating said elements separately by the forward travel of said gripper unit, and operable means under the control of the pivotal jaw of said gripper unit and responsive to the closing movement of said jaw for operating said controlling member and positioning the same Wlth respect to said elements according to the extent of said jaw movement, whereby said second element will be engaged and actuated by said controlling member when no signature or sheet is `gripped by said gripper unit, and said first element will be engaged and actuated by said controlling member when plural signatures or sheets are simultaneously gripped by said gripper unit.

17. Apparatus as defined in claim 6, comprising operable control means associated with each hopper and located between the end limits of reciprocating movement of the gripper unit correlated to said hopper, said control means comprising a first vertically disposed pivotal element, means responsive to the operation of said element to stop the machine, a second vertically disposed pivotal element located rearwardly of and in line with said rst element, said second element projecting below the lower extremity of said first element and being adapted when actuated to engage and actuate said first element, means mounting said second element for movement bodily relative to said first element to an inoperative position with the lower extremity thereof disposed above the lower extremity of said first element, and a pendulum member operably `connected to said second element for moving the latter to said inoperative position, said pendulum member being mounted to extend into the plane of the bite of the jaws of said gripper unit so as to be engaged and actuated by and through movement of the signature or sheet gripped by said jaws, and for each gripper unit a controlling finger reciprocal therewith and arranged thereon to be projected upwardly relative thereto exteriorly thereof so as to separately engage and actuate said elements by the forward travel of said gripper unit, biasing means operably connected to said controlling finger and tending at all times to project the same, means for restraining said controlling finger against movement by said biasing means while the pivotal gripper jaw is open and allowing for such movement while said jaw moves to closed gripping position, and a controlling arm connected to and operated by said jaw through movement thereof to closed position for determining the projected positions of said controlling linger according to the extent of said jaw movement, whereby said second element in its operative position will be engaged and actuated by said controlling finger when no signature or sheet is gripped by said gripper unit, and said first element with said second element in its inoperative position will be engaged and actuated by said controlling linger when plural signatures or sheets are simultaneously gripped by said gripper unit and will not be engaged by said controlling nger when only a single signature or sheet is gripped by said gripper unit.

18. Apparatus as defined in claim l7 wherein said biasing means comprises a lever pivotally mounted at one end thereof on said gripper unit and having pivotally connected thereto at the other end thereof said controlling finger, said lever being arranged to be engaged by said controlling arm, and a spring acting upon said lever to yieldingly impart upward pivotal movement thereto.

19. Apparatus as defined in claim 181, comprising an adjustable abutment member carried by said lever and interposed between the latter and said controlling arm.

20. Apparatus as defined in claim 18 wherein the restraining means comprises a latch member pivotally mounted on the gripper unit and operable by the controlling arm in response to the opening movement of the pivotal gripper jaw to engage said lever and depress and hold the same in depressed position with said controlling finger disposed clear of the lower extremities of the first and second elements, said latch member being released by said controlling arm in response to the closing movement of said gripper jaw and when so released enabling pivotal movement of said lever by said spring.

2l. Apparatus as defined in claim l7 wherein said responsive means for stopping the machine functions to break an electric circuit.

22. Apparatus as defined in claim 17 wherein said responsive means for stopping the machine comprises an arm releasably supported by said first element in raised position and against pivotal downward movement, and a mercury switch carried by said arm, said switch being closed when said arm is supported by said element and being connected in an electric circuit for maintaining the machine in operation, dropping of said arm when released by said element upon actuation of the latter causing opening of said switch and breaking of said circuit.

23. Apparatus as defined in claim 22, comprising resilient means operably connected to said arm for yieldingly holding the same in engagement with said first element and for imparting downward pivotal movement thereto when released by said element.

24. Apparatus as defined in claim 22, comprising adjustable means mounting said first element, said arm and said switch for adjustment as a unit toward and away from said controlling finger to accommodate signatures 01- sheets of different thicknesses that may be handled, and means for so adjusting said mounting means.

25. Apparatus as defined in claim 22, comprising a visual signal connected in said electric circuit and electrically operated in response to the breaking of said circuit 23 through opening of said switch, said signal being discontinued upon restoring said arm to its normal raised position and closing of said switch and said circuit thereby.

26. In a signatureV or sheet handling machine, an operable body adapted to convey a signature or sheet and having a signature or sheet gripping surface thereon, means for operating said body, a gripper jaw pivotally mounted on said body, means for moving said jaw toward said surface to closed position on a signature or sheet, a controlling member mounted on said body and projecting eXteriorly thereof, a control element independent of said body and arranged to be engaged and actuated by said controlling member through movement of said body, means mounting said control element for movement to an inoperative position with respect to said controlling member, and means operably connected to said mounting means and actuated by the signature or sheet in transit gripped by said jaw for moving said control element to its inoperative position whereby engagement thereof by said controlling member is avoided.

27. In a signature or sheet handling machine, an operable body adapted to convey a signature or sheet and having a signature or sheet gripping surface thereon, means for operating said body, a gripper jaw pivotally mounted on said body, means for moving said jaw toward said surface to closed position on a signature or sheet, a controlling member mounted on said body and arranged to be projected relative thereto exteriorly thereof, operable means mounted on said body for projecting said controlling member while said jaw moves to closed position, a control element independent of said body and arranged to be engaged and actuated by said controlling member in projected position through movement of said body, means mounting said control element for movement to an inoperative position with respect to said projected controlling member, and means operably connected to said mounting means and actuated by the signature or sheet in transit gripped by said jaw for moving said control element to its inoperative position whereby engagement thereof by said projected controlling member is avoided.

28. In a signature of sheet handling machine, an operable body adapted to convey a signature or sheet and having a signature or sheet gripping surface thereon, means for operating said body, a gripper jaw pivotal-ly mounted on said body, means `for moving said jaw toward said surface to closed position on a signature or sheet, a controlling member mounted on said body and arranged to be projected relative thereto exteriorly thereof, means mounted on said body and operable in response to the closing movement of said jaw for projecting said controlling member, a control element independent of said body and arranged to be engaged and actuated by said controlling member in projected position through movement of said body, means mounting said control element for movement to an inoperative position with respect to said projected controlling member, and means operably connected to said mounting means and extending into the plane of said surface so as to be engaged and actuated by the signature or sheet in transit gripped said jaw for moving said control element to its inoperative position whereby engagement thereof by said projected controlling member is avoided.

.29. In a signature or sheet handling machine, an operable body adapted to convey a signature or sheet and having a signature or sheet gripping surface thereon, means for operating said body, a gripper jaw pivotalfly mounted on said body, means for moving said jaw towa-rd said surface to closed position on a signature or sheet and for moving said jaw away from said surface to open position to release the signature or sheet gripped thereby, a controlling member mounted on said body and arranged to be projected relative thereto exteriorly thereof, means on said body and operable in response to the closing movement of said jaw for projecting said controlling member, a `second Y controlling member mounted on said body and operable by said jaw through closing movement thereof for limi-ting the project-ion of said first-named controlling member to Yone position when only a single signature o-r sheet is gripped by said jaw, and enabling projection thereof to another position when plural signatures or sheets are simultaneously gripped by said jaw, and a control element independent of said body and arranged to be engaged and actu-ated by said first-named cont-rolling member in the said another projected position thereof by the mov-ement of said body and to avoid engagement thereof by said first-named controlling member in the said one projected position thereof.

30. Apparatus as defined in claim 29, comprising a latch member mounted on said body and operable by said second controlling member in response to the opening movement of said jaw for retracting said first-named controlling member and holding the same in retracted position, said latch member being released by said cont-rolling member in response to the closing movement of said jaw.

3l. In a signature 0r sheet handling machine, an opera-ble body adapted to convey a signature or sheet and having a signature or sheet gripping surface thereon, means for operating said body, a gripper jaw pivotally mounted on said body, means for moving said jaw toward said surface to closed position on a signature or sheet and for moving said jaw away from said surface to open position to release the signature Vorsheet gripped thereby, a controlling member mounted on said body and arranged to be projected relative thereto eXteri-orly thereof, means on said body and operable in response to the closing movement of said jaw for projecting said controlling member, a second controlling member mounted on said body and operable by said ja-w through closing movement thereof for limiting the projection of said first-named controlling member t0 a first position when no signature or sheet is gripped by said jaw, to a second position when only a single signature or sheet is gripped by said jaw, and enabling projection thereof to a rthird position when plural signatures or sheets are simultaneously gripped by said jaw, a first control element independent of said body and `arranged to be engaged land actuated by said first-named controlling member in said third projected position thereof by the movement of said body, a second control element independent of said body and arranged to be engaged and actuated by said firstnamed controlling member in said first projected position thereof by the movement of said body and to, in turn, engage and actuate said first control element, said firstnamed controlling member in said second projected position thereof failing to engage and actuate said first control element, means mounting said second control eleiment for movement relative to said lirst control element to an inoperative position with respect t-o said first-named controlling member, and means operably con-nected to said mounting means and actuated by the signature or sheet in transit gripped by said jaw for moving said second control element to its inoperative position.

32. Apparatus as defined in claim 3l, comprising a latch member mounted on said body and operable by said second controlling member in response to the opening movement of said jaw for retracting said first-named controlling member to its original position clear of said firs-t and second control elements and holding the same in said position, said latch member being released by said contro-lling member in re-sponse to the closing movement of said jaw.

33. In a signature or sheet handling machine, a-n operable body adapted to convey a signature or sheet and having a signa-ture or sheet gripping surface thereon, mean-s for operating said body, a gripper jaw pivotally mounted on said body, means for moving sai-d jaw toward said surface to closed posit-ion on a signature or sheet and Ifor moving said jaw away from said surface to open position to release the signature or sheet gripped thereby, a

controlling finger mounted on said, body and arranged to be projected upwardly relative thereto exteriorly thereof, lbiasing means on said body and operably connected to said finger and tending at all times to project the same, means on said body for restraining said finger against projection by said biasing means while said jaw is open and allowing such movement while said jaw moves to closed position, a controlling arm mounted on said body 'and operable by said jaw through closing movement thereof for limiting the projection of said finger to a fir-st lower position when no signature or sheet is gripped by said jaw, to a sec-ond higher position when only a single signature or sheet is gripped by said jaw, and enabling projection thereof to a third still higher position when plural signatures or sheets are simultaneously gripped by said jaw, a first vertically disposed pivotal contnol element independent of said body and arranged to be engaged and actuated lby said finger in said third projected position thereof by Ithe movement of said body, a second vertically disposed pivotal -control element independent of said body and arranged t-o be engaged and actuated by said finger in said first projected position thereof by the movement of said body, said second control element projecting below the lower extremity of said lfirst control element and being adapted when actuated to engage and actuate said first control element, said finger in said second projected position thereof failing to engage and actuate said first control element, means mounting said second control element for movement bodily relative to said first control element to an inoperative position with respect to said finger, and a pendulum member operably connected to said mounting means and actuated by the signature or sheet in transit gripped by said jaw for moving said second control element to said inoperative position, said pendulum member being mounted to extend into the plane of said surlace.

34. Apparatus as defined in claim 33 wherein said biasing means comprises a lever pivotally mounted at one end thereof on said body and having pivotally connected thereto at the other end thereof said controlling linger, said lever being arranged to engage and to be engaged by said controlling arm, and a spring acting upon said lever to impart upward pivotal movement thereto.

35. Apparatus as defined in `claim 34, comprising an adjustable abutment carried by said lever and interposed between the latter and said controlling arm.

36. Apparatus as defined in claim 34 wherein the restraining means comprises a latch member pivotally mounted on said body and arranged to engage said lever, said latch member being operated by said controlling arm in response to the opening movement of said gripper t said arm for yieldingly holding the same in engagement with said element and for imparting downward pivotal movement thereto when released by said element upon actuation of the latter.

38. Apparatus as defined in claim 37, comprising a mercury type control switch carried by said arm, dropping of said arm when released by said first control element effecting actuation of said switch.

39. Apparatus as defined in claim 37, comprising a stationary bracket, a movable bracket having said control arm and said first control element mounted thereon, a spring-pressed friction disc carried by said movable bracket and engaged with said stationary bracket for mounting and movably holding said movable bracket on said stationary bracket and providing for sliding vertical adjustment of said movable bracket, a vertical stem secured to said movable bracket and projecting upwardly therefrom through a clearance opening in said stationary bracket, a compression spring surrounding said stem and disposed between said brackets, and an adjusting nut threaded on the upper end of said stem and engaging against said stationary bracket.

40. In a signature or sheet handling machine, an operable body adapted to convey a signature or sheet, means for operating said body, means on said body for gripping va signature or sheet, control means independent of said body and movable to operative and inoperative positions, said control means being normally disposed in said operative position, controlling means on said body and arranged to engage and actuate said control means through movement of said body, and means actuated by the signature or sheet in transit for moving said control means to said inoperative position whereby engagement thereof by said controlling means is avoided.

References Cited in the file of this patent 

